This invention generally relates to a method and apparatus for positioning a web in a printer and, more particularly, relates to an apparatus for accurately locating a selected type row on the web with respect to the print line of the print mechanism of the printer.
The rapid growth of data communications systems over the last few years has greatly increased the demand for and availability of high speed alphanumeric printers which type informational data in readable form upon a paper web. A particular form of printer enjoying widespread acceptance is the impact printer wherein a plurality of character dies are conveyed on a continuously moving endless carrier past print hammers. The incoming data information is processed and used to drive the print hammers which force selected type characters against the paper web. A printer utilizing this arrangement is described in U.S. Pat. No. 3,822,641 entitled "Impactor Assembly for Printer" by E. S. Babler issued on July 9, 1974, and U.S. Pat. No. 3,742,848 entitled "Endless Carrier Printer" by F. E. Huntoon et al. issued on July 3, 1973, both references having a common assignee with this application.
A particular inconvenience which an operator experiences when using such impact printers is the difficulty of positioning a selected type row on the web with the print line of the print mechanism. This situation frequently occurs during the preparation of a prepared form whereon information is to be typed at a selected location on the paper web. In such aforementioned printers, the print mechanism is so constructed that the print line is obstructed from the operator's view; the row which is being typed being visible only after the web has advanced. Thus, it is particularly advantageous for such printers to include means for accurately positioning a selected type row on the print line thereof.
The illustrated embodiment is directed to a print line reference clip which allows the operator to accurately position type at a selected location on the paper web even though the print line of the printer is obstructed from the operator's view.